Advanced Endodontics R Nageswar Rao
Chapter Notes

Save Clear

1Advanced Endodontics
“There is always the hope of tomorrow to brighten the clouds of today, There's always a corner for turning, no matter how weary the way. So just look ahead to tomorrow and trust that you'll find waiting there, The sunlight that seemed to be hidden by yesterday's clouds of despair.”
3Advanced Endodontics
R Nageswar Rao MDS Chairman Former Professor and Head Department of Conservative Dentistry and Endodontics SDM College of Dental Sciences and Hospital Dharwad, Karnataka, India
4Published by
Jitendar P Vij
Jaypee Brothers Medical Publishers (P) Ltd
Corporate Office
4838/24, Ansari Road, Daryaganj, New Delhi 110 002, India, Phone: +91-11-43574357, Fax: +91-11-43574314
Registered Office
B-3, EMCA House, 23/23B Ansari Road, Daryaganj, New Delhi 110 002, India
Phones: +91-11-23272143, +91-11-23272703, +91-11-23282021, +91-11-23245672, Rel: +91-11-32558559
Fax: +91-11-23276490, +91-11-23245683, e-mail:, Website:
North America Office
1745, Pheasant Run Drive, Maryland Heights (Missouri), MO 63043, USA Ph: 001-636-6279734
Central America Office
Jaypee-Highlights Medical Publishers Inc., City of Knowledge, Bld. 237, Clayton, Panama City, Panama Ph: 507-317-0160
Advanced Endodontics
© 2009, R Nageswar Rao
All rights reserved. No part of this publication should be reproduced, stored in a retrieval system, or transmitted in any form or by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the author and the publisher.
First Edition: 2009
Typeset at JPBMP typesetting unit
Printed at
All my
Postgraduate Students
Universität Zürich
Centre of Dental and Oral Medicine
All great rivers have humble origins. From its modest beginning in 1986, the SDM College of Dental Sciences and Hospital, Dharwad, Karnataka has grown into the foremost institution of dental medicine in India in a relatively short span of two decades. The college has been imparting undergraduate and postgraduate dental education of a high standard, conducting research and providing oro-facial health care to the rural population around Dharwad and beyond. It has been training dental health care personnel of different skills and various levels.
I had the rare honour to associate myself with the College from its very inception. Therefore, it is a matter of great professional pride and satisfaction for me to note that the SDM College is the only one among the 161 dental colleges in the country to have received the ‘Five Star’ accreditation from the National Assessment and Accreditation Council (NAAC) of India. It was also the first and now one of the two centres in India for primary examinations leading to the FDSRCS and the FRCS of the Royal College of Surgeons, Glasgow, United Kingdom. It is, therefore, not incidental that the SDM College of Dental Sciences and Hospital has several scores of publications in international journals and has accumulated expertise and materials that can be shared with students, researchers and teachers.
The Advanced Endodontics by Dr R Nageswar Rao, Head of the Department of Conservative Dentistry and Endodontics, SDM College of Dental Sciences, is an example of that cumulated experience and wisdom. The book is the worthy successor to Professor Rao's first book entitled the Diagnostic Methods in Endodontics, sharing his extensive experience in teaching, research and patient care.
The word Endodontics is derived from the Greek words endo meaning inside and odons meaning tooth (inside the tooth). And Endodontology is the study of the form, function, health and diseases of the dental pulp and periradicular tissues, their prevention and clinical management. Root canal treatment is the procedure used by endodontics to save a tooth that would otherwise be removed due to pulpal infection and disease. During the past decade there have been unprecedented advances in the understanding of the biological basis of the disease and the technology to deal with it clinically. TheAdvanced Endodontics is a valiant attempt to consolidate the principles and practice of endodontics for the benefit of dental students and teachers in the country.
Research Professor
Department of Restorative Dentistry and Endodontology
University of Connecticut Health Centre
Farmington, Connecticut, USA
Visiting Professor
Eastman Dental Institute
University College London
London, UK
Endodontics is a branch of dentistry that deals with the tooth pulp and its diseases. It is gaining importance due to patients's increasing awareness of dental health, prevention, saving teeth and oral hygiene. There is a demand for a painless alternative to extraction to save the teeth and this alternative is root canal therapy. The 21st-century endodontics with all its advancements is on the way to solve the existing numerous difficulties. The ultimate goal of modern endodontics is to effectively shape the root canals to facilitate thorough cleaning of entire system with less time consumption leading to easy and effective obturation.
Advanced Endodontics is meant mainly for postgraduate students. It includes the most recent developments in the field of endodontics.
From diagnosis to periapical surgery, there have been significant changes, both in concept and equipment. Recently, tissue engineering has been used to revitalize dentin and pulp tissue.
In modern practice, proper diagnosis is the key for the success of endodontic treatment. This starts with a good relevant case history, clinical examination and diagnostic tests, which form an indispensable part of diagnostic system. The new methods of assessing pulp vitality like Laser Doppler flowmetry, Infrared thermographic imaging, pulse oxymetry, liquid crystal testing and Hughes probe eye camera are presently experimental and mainly research oriented and are expected to be clinical tests in the forthcoming days. Digital radiography and electronic apex locators have also revolutionized clinical endodontics. DNA and RNA based microbiological techniques to detect uncultivable microorganisms, i.e. Polymerase chain reaction and Microarray technology are used to identify and study a large array of genes. A relationship between clinical symptoms and inflammatory molecules has been demonstrated reporting the significance of substance ‘P’.
“Access is success” should always be borne in mind during endodontic treatment. A detailed knowledge of pulp chamber and root canal anatomy is required for success of endodontic treatment. There are various methods to determine exact working length including radiographic method and apex locators. Digital radiography has also revolutionized the clinical endodontics A film less technique commercially developed to reduce radiation exposure, is used to ‘digitalize’ the image that can be analyzed, measured and manipulated. Recently use of apex locators is considered to be the advanced method to determine the working length. First generation apex locators had disadvantages which have been overcome now by using third and fourth generation apex locators. These are reported to be very accurate in the determination of working length.
One of the key advancement in endodontic practice is operating microscope. It provides magnification and illumination and is useful for locating the canals after the access is made, and is necessary to address anatomical complexities and procedural complications associated with difficult cases. Enhanced vision, coaxial lighting and improved optics helps in identifying miniature canal openings, remnant pulp tissue and incipient fracture lines. The introduction of endoscopes at the turn of millennium involves using a fiberoptic probe to explore internal and external components of root canal aiding clinician in diagnosis and also to communicate and educate the patient.
The cleaning and shaping of the canal is one of the important preliminary requisite for endodontic treatment. There are various changes made in the endodontics instrument material and design. Nickel titanium (NiTi) files have become a mainstay in most endodontic procedures. Because of their property of shape memory and superelasticity, these files can be effectively used in curved canals for debridement. Varying the taper of the instrument leads to a more efficient preparation of root canal space. While biomechanical preparation can reduce the bacterial count significantly; mechanical debridement does not disinfect root canal system completely. Thus, a root canal irrigant is needed to aid in the debridement. Various techniques and irrigating solutions are currently used to attain disinfection. Recently MTAD has been introduced as a final rinse for disinfection of root canal system. This irrigant is able to remove the smear layer safely, and it is more effective disinfectant than NaOCl even against resistant bacteria such as Enterococcus faecalis.8
After proper cleaning and shaping and disinfection of root canal system, proper obturation of the canal is necessary to prevent reinfection. Different techniques of gutta-percha compaction have undergone various modifications in their insertion and compaction techniques. In older days torch or open flame was used to seal or melt the gutta-percha. This technique is now called “Flintstone” age endodontics. The system B and Touch-n-Heat allows a safer means to heat the gutta-percha. Delivery systems like Obutra II and solid core carriers like Thermafil and Simplifil have become a necessity in modern endodontic practice.
Ultrasonic devices have become essential tools for cleaning the isthmus after access preparation, assisting the removal of posts and separated instrument, root end preparation during surgical treatment of root canals, and searching for the calcified canals.
Lasers have various applications in endodontics such as measuring pulp vitality, preparing and disinfecting root canals and performing endodontic surgery. These devices offer a thin fiberoptic delivery system entering narrow root canals. Other applications of lasers include hemostasis, sterilization of root canals and smear layer and debris removal and even gutta-percha removal.
In spite of advancements in modern endodontic technology there are certain problems that may occur during or after treatment. Most common problems are broken instruments and perforations. Many kits have evolved for the removal of broken instruments from the canal like Masserian kit; Ruddles instrument removal system, etc., Management of perforations in the older times was done using calcium hydroxide, zinc oxide, and GIC during treatment or retreatment. Recently the advent of new material MTA (Mineral trioxide aggregate) has revolutionized endodontics. MTA has been used successfully in the repair of lateral root perforations and furcal perforations, vital pulp capping agent, apical plug in one visit apexification and as a root-end filling material and also as a coronal sealing material. A variety of new retrograde filling materials can be used which includes Super EBA, IRM, and Dentin bonding agents and most recently MTA and VERRM.
The science of endodontics has undergone significant changes which have resulted in improved treatment outcomes and an opportunity to preserve the natural dentition. These objectives can be achieved with less morbidity and more predictability. Compilation of more current clinical data that are based on procedures performed with more advanced techniques will provide a more accurate rate of healing after non-surgical and surgical endodontic therapy. The future holds the promise of continued growth of research knowledge and systematic reviews which will provide most valuable evidence connecting the patient, the clinician, the policy maker, the benefit purchaser and benefit provider in the decision-making process.
Endodontics is growing with rapidly changing treatment modalities in accordance with advancements in the technology leading to the precision in treatment outcome. No other branch in dentistry is changing at this rate. Procedures from access cavity preparation, Microscopes, Apex locators, Rotary instrument systems, Obturating systems and Surgical endodontics to tissue engineering have changed to an extent to appreciate the results clinically. The book in the form of Advanced Endodontics is the contribution of my vast experience to the profession.
In this regard I am extremely grateful to our Principal Dr C Bhasker Rao, who encouraged me throughout my career. I would like to thank Dr PNR Nair BVSc, DVM, PhD, Senior Scientist, Department of Oral and Structural Biology, Center of Dental and Oral Medicine, University of Zurich, Switzerland, who wrote the foreword of this book and has given me valuable suggestions.
My immense thanks to Dr Priya Horatti, Professor Department of Conservative and Endodontics for her contribution in this book. I would also like to thank all staff members of Conservative Department. It is my pleasure to acknowledge Dr Manjunatha RK postgraduate student who helped me in bringing out this book, and also all postgraduate students in the department of Conservative for their constant feedback and support.
It is my privilege to thank M/s Jaypee Brothers Medical Publishers (P) Ltd to bring this book for final shape.
I would like to thank Pujyashree Veerendra Heggade, President SDME Society for encouraging me to bring out this book. I would like to thank Mrs Suvarna SK, Computer Operator for helping in graphics and other book work.
Last but not the least, I would like to thank each and every person who has in some way or the other helped me.
R Nageswar Rao